Digital Image Ballistics from JPEG Quantization: A Followup Study

Dartmouth Technical Report TR2008-638

	Hany Farid

Date: December 2008

URL (PDF): <http://www.cs.dartmouth.edu/reports/TR2008-638.pdf> (264KB)

Abstract:
 The lossy JPEG compression scheme employs a quantization table that
 controls the amount of compression achieved. Because different cameras
 typically employ different tables, a comparison of an image's
 quantization scheme to a database of known cameras affords a simple
 technique for confirming or denying an image's source.  This report
 describes the analysis of quantization tables extracted from 1,000,000
 images downloaded from Flickr.com.